How well does clot-busting drug work in stroke patients?

MAYWOOD, Ill. — The clot-busting drug rt-PA remains the most beneficial proven emergency treatment for strokes caused by blood clots, according to an editorial in the November issue of Archives of Neurology by Dr. José Biller.

“The benefits of treatment outweigh the risks in patients treated with intravenous rt-PA within 4.5 hours of symptom onset,” Biller wrote. Biller is chairman of the Department of Neurology at Loyola University Chicago Stritch School of Medicine and an internationally recognized expert on stroke care.

Most strokes are ischemic, meaning they are caused by blood clots that block blood flow in the brain. Brain cells begin dying when they are starved of blood supply. But if administered soon enough, an IV drug known as recombinant tissue plasminogen activator (rt-PA) can dissolve clots, restore blood flow and limit damage.

Biller’s editorial is about a study, published in the same issue, by Dr. Ioan-Paul Muresan and colleagues at Assistance Publique — Hopitaux de Paris. The study found that stroke patients who show improvement within one hour of receiving rt-PA were more likely to do well three months later,

Researchers followed 120 patients who received rt-PA and found that 22 (18.3 percent) showed significant improvement within one hour of treatment. After three months, 15 of these patients (68.2 percent) had a favorable outcome. By comparison, only 29.6 percent of patients who did not show early improvement had a favorable outcome at three months.

These findings suggest that a quick bedside assessment “can predict good response,” Biller wrote. Conversely, a poor response in the first hour can predict a poor outcome at three months. In such cases, physicians “can begin consideration of mechanical interventions, intra-arterial therapy or other alternative therapies.”

Additional studies involving larger populations at multiple centers “are needed to address the significance and clinical utility of the intriguing findings of this carefully conducted study,” Biller wrote.